1. Field of the Invention
The embodiments of the invention generally relate to fin-type field effect transistors (FINFETs) and more particularly to curved or bent fins within such FINFETs.
2. Description of the Related Art
The aspect of and methods of manufacture of FINFETs with straining layers is well-known to those ordinarily skilled in the art as evidenced by U.S. Patent Publications 2005/0093154; 2004/0195624; and 2004/0061178 the complete disclosures of which are incorporated herein by reference.
As explained in U.S. Patent Publication 2005/0227498, the complete disclosure of which is incorporated herein by reference, field effect transistors fabricated on an SOI structure include a channel formed in the active silicon layer. Carrier mobility is an important parameter because of its direct influence on output current and switching performance of the field effect transistors. Accordingly, one approach for increasing device performance is to enhance the channel mobility by straining the active silicon layer. A net strain may be provided by introducing compressive stress into the silicon active layer or by introducing tensile stress into the silicon active layer. Straining the crystal lattice in the plane of the silicon layer either locally or globally alters the electronic band structure of the silicon layer. As a result, in-plane carrier mobility may be increased by ten to twenty-five percent, which results in improved device performance.